Systems, methods, and devices for removing contaminants from stormwater

ABSTRACT

A stormwater treatment device may include a chamber having a floor and a wall; an inlet formed in the wall that receives stormwater into an inlet side of the chamber; an outlet formed in the wall that discharges stormwater from an outlet side of the chamber; an enhanced settling device positioned in the outlet side of the chamber; a flow diverter plate in a lower portion of the chamber; and an outlet control diverter positioned proximate to the outlet. Stormwater is received by the inlet in a first flow direction, flows from the inlet side to the lower portion of the chamber in a second flow direction, flows through the enhanced settling device to an upper portion of the chamber in a third flow direction, flows through the outlet control diverter in fourth flow direction, and is discharged by the outlet in a fifth flow direction.

BACKGROUND OF THE INVENTION 1. Field of the Invention

The present disclosure relates generally to systems, methods, anddevices for removing contaminants from stormwater.

2. Description of The Related Art

When it rains, stormwater travels over a variety of surfaces before itreaches a sewer. Along its path, the stormwater picks up and suspendscontaminants, both natural and man-made, and carries the contaminants tothe sewer. The sewer provides a first opportunity to remove some ofthese contaminants from the stormwater before the stormwater continuesits journey to a body of water.

SUMMARY OF THE INVENTION

Systems, methods, and devices for removing contaminants from stormwaterare disclosed.

According to an embodiment, a stormwater treatment device may include achamber having a floor and a wall; an inlet formed in the wall thatreceives stormwater into an inlet side of the chamber; an outlet formedin the wall that discharges stormwater from an outlet side of thechamber; a vertical baffle that divides at least a portion of thechamber into the inlet side and the outlet side, wherein the inlet sideand the outlet side are in fluid communication; an enhanced settlingdevice positioned in the outlet side of the chamber, wherein a portionof the chamber below a bottom of the enhanced settling device defines alower portion of the chamber, and a portion of the chamber above a topof the enhanced settling device defines an upper portion of the chamber;a flow diverter plate in the lower portion of the chamber; and an outletcontrol diverter positioned proximate to the outlet; wherein stormwateris received by the inlet in a first flow direction, flows from the inletside to the lower portion of the chamber in a second flow direction,flows through the enhanced settling device to an upper portion of thechamber in a third flow direction, flows through the outlet controldiverter in fourth flow direction, and is discharged by the outlet in afifth flow direction.

In one embodiment, the stormwater treatment device may also include oneor more vanes positioned on the vertical baffle, wherein the pluralityof vanes extend into the inlet side of the chamber.

In one embodiment, a horizontal vane may be positioned on the verticalbaffle, and may extend into the inlet side of the chamber. In addition,a plurality of vertical vanes may be provided, and the vertical vanesmay extend from the ends of the horizontal vane.

In one embodiment, the enhanced settling device may include a pluralityof tubes and each tube is positioned at an angle from the wall towardthe vertical baffle. In one embodiment, the angle may be different foreach tube, for a plurality of tubes, etc.

In one embodiment, the enhanced settling device may include a pluralityof tubes, and a first subset of the plurality of tubes is positioned ata first angle to the horizontal, and a second subset of the plurality oftubes is positioned at a second angle to the horizontal.

In one embodiment, a top of the enhanced settling device may be below alower surface of the outlet control diverter.

In one embodiment, stormwater having a flow rate above a certain valueflows over the vertical baffle.

In one embodiment, the outlet control diverter may include a bottompiece and two vertical side pieces, wherein an opening for receivingstormwater is defined by the bottom piece, at least one of the verticalside pieces, and the wall.

In one embodiment, the changes in flow direction optimize a time thestormwater spends in the chamber.

In one embodiment, the chamber may be cylindrical.

According to another embodiment, a method for removing suspendedcontaminants from stormwater may include: (1) receiving, at an inlet ofa stormwater treatment device, stormwater containing suspendedcontaminants, wherein the stormwater flows into an inlet side of thestormwater treatment device and a fluid velocity of the stormwaterdecreases; (2) receiving, in a lower portion of the stormwater treatmentdevice, the stormwater; (3) receiving, in an enhanced settling device,the stormwater from the lower portion, wherein the stormwater changesdirection to flow up the enhanced settling device into an upper portionof the chamber on an outlet side of the chamber; (4) receiving, at anoutlet control diverter, the stormwater from the upper portion, whereinthe stormwater changes direction to be received by the outlet controldiverter; and (5) discharging, at an outlet, the stormwater.

In one embodiment, the enhanced settling device may include a pluralityof tubes, and a first subset of the plurality of tubes is positioned ata first angle to the horizontal, and a second subset of the plurality oftubes is positioned at a second angle to the horizontal.

In one embodiment, a top of the enhanced settling device may be below alower surface of the outlet control diverter.

In one embodiment, stormwater having a flow rate above a certain valueflows over a vertical baffle into the upper portion of the stormwatertreatment device.

In one embodiment, the outlet control diverter may include a bottompiece and two vertical side pieces, wherein an opening for receivingstormwater is defined by the bottom piece, at least one of the verticalside pieces, and the wall.

In one embodiment, the changes in flow direction optimize a time thestormwater spends in the chamber.

In one embodiment, the chamber may be cylindrical.

According to another embodiment, a system for removing contaminants fromstormwater may include a chamber with a horizontal floor and verticalwalls attached to the floor, where the chamber walls form a cylinder andthe inlet and outlet are on opposite side of the cylinder; an inlet inone wall for receiving contaminated stormwater and an outlet in the wallfor discharging treated stormwater; a vertical baffle in the chamberthat is perpendicular to the vertical plane bisecting the inlet andwhich divides the chamber into an inlet side and an outlet side, wherethe outlet side is between the baffle and the outlet opening and theinlet side is between the baffle and the inlet opening, the two sidesbeing in fluid communication; a stack of lamellar tubes positioned inthe outlet side, where the long axis of each tube is at an angle tohorizontal approximately perpendicular to the vertical plane bisectingthe inlet, where the top of the stack of tubes is at least 6 inchesbelow the invert of the outlet; one or more flow diversion platesattached to the walls of the chambers on the outlet side below the stackof lamellar tubes; and a flow diverter placed at the entrance to theoutlet.

In one embodiment, the walls of the chamber may form a rectangular prismstructure.

In one embodiment, the angle between the vertical plane bisecting theinlet and a vertical plane bisecting the outlet is between 45 and 315degrees.

In one embodiment, the top of the vertical baffle is at a level abovethe invert of the inlet pipe such that at flow rates exceeding thedesign flow rate water will pass over top of the vertical baffle.

In one embodiment, the bottom of the vertical baffle is at least 2 feetfrom the bottom of the chamber.

In one embodiment the vertical baffle may have one or more vanesextending perpendicular from the baffle towards the inlet.

In one embodiment the at least two vanes may extend 1-5″ from the baffle

In one embodiment the at least two vanes are placed 3-6″ from the pointwhere the baffle meets the wall of the tank on each side of the bafflesuch the arrangement of vanes is symmetrical about a vertical planebisecting the inlet.

In one embodiment, the long axis of each tube is at an angle of 50 to 70degrees from horizontal and the direction of this angle is between 45and 135 degrees to the vertical plane bisecting the inlet.

In one embodiment, where the bottom of the stack of lamellar tubes isabove the bottom of the vertical baffle.

In one embodiment, the flow diversion plates are planar and at least oneplate is attached to the wall below the outlet such that the plate hasthe same centerline as the outlet and the plate forms an angle ofbetween 45 degrees to 135 degrees from horizontal. Second flow diversionplates may be attached to the wall in the direction of the angle of thelamellar tubes such that the centerline of the plate coincides with thecenterline of the wall. Third flow diversion plates may be attached tothe wall opposite the second flow diversion plate such that thecenterline of the plate coincides with the centerline of the wall. Thesecond and third flow diversion plates may or may not be at the sameangle to horizontal as the first diversion plate, within the range of 45to 135 degrees. In one embodiment, more than one flow diversion platesmay be manufactured as a single piece.

In one embodiment, the sagitta of each diversion plate may be between 3and 14 inches.

In one embodiment, the flow diverter at the outlet may include ahorizontal bottom piece at the same elevation as the outlet invert andtwo vertical side pieces, a first vertical side piece projecting fromone side of the outlet opening, parallel to a vertical plane bisectingthe outlet and a second vertical side piece substantially perpendicularto the first vertical side piece and parallel to a tangent to thechamber wall at the midpoint of the outlet, the bottom piece and twovertical side pieces forming an opening through which water can reachthe outlet opening.

In one embodiment, the second vertical side piece may be curved.

In one embodiment, the flow diverter at the outlet may include a firstvertical side piece projecting at least 6 inches from one side of theoutlet opening and a second vertical side piece at least 8 inches inlength. The flow diverter at the outlet may include two vertical sidepieces projecting at least 4 inches up from the horizontal side piece.

In one embodiment, the flow diverter at the outlet may include anopening through which water can reach the outlet opening that is on theopposite side of the outlet side from the angle of the lamellar tubessuch that water flowing through the tubes must reverse direction atleast twice in order to enter the opening in the flow diverter.

In one embodiment, the flow diverter at the outlet may include anopening through which water can reach the outlet opening that is atleast 6 inches wide.

BRIEF DESCRIPTION OF THE DRAWINGS

For a more complete understanding of the present disclosure, the objectsand advantages thereof, reference is now made to the followingdescriptions taken in connection with the accompanying drawings inwhich:

FIG. 1 depicts an isometric view of a stormwater treatment deviceaccording to an embodiment;

FIGS. 2A and 2B depict exemplary vane implementations according toembodiments;

FIG. 3 depicts a side elevation view of the stormwater treatment deviceof FIG. 1 according to an embodiment;

FIG. 4 depicts a front elevation view of the stormwater treatment deviceof FIG. 1 according to an embodiment;

FIG. 5 depicts a plan view of a first, second, and third flow divertersaccording to an embodiment;

FIG. 6 depicts a plan view of the stormwater treatment device of FIG. 1according to an embodiment;

FIG. 7 depicts a cross-section view of a lamellar tube according to oneembodiment;

FIG. 8 depicts a side view of a lamellar tube according to oneembodiment;

FIGS. 9 depicts an isometric view of a stormwater treatment deviceaccording to another embodiment;

FIGS. 10 depicts a side view of a stormwater treatment device accordingto the embodiment of FIG. 9 showing the interior of the inner chamber;and

FIG. 11 depicts a method for removing contaminants from stormwateraccording to one embodiment.

DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS

Embodiments are directed to system for removing contaminants fromstormwater. Referring to FIGS. 1-8 , views of a stormwater treatmentdevice are provided according to an embodiment.

Stormwater treatment device 100 may define a chamber including inlet105, outlet 110, wall 115, vertical baffle 120, one or more flowdiverters 130, and outlet control diverter 135. In one embodiment,stormwater carrying contaminants may enter inlet 105 and may flow tolower portion 150 of stormwater treatment device 100. In one embodiment,depending on the inflow speed of the stormwater, the stormwater may hitvertical baffle 120, slow, and flow downward.

In one embodiment, the distance of vertical baffle 120 from inlet 105may be a balance between having more elements in enhanced settlingdevice 125 and having an opening to allow for cleaning and servicing. Asmaller distance may provide better performance, but may make cleaningand servicing more difficult. In addition, a smaller distance may alsoincrease scour.

In one embodiment, vertical baffle 120 may be positioned and/or sizedsuch that the top of vertical baffle 120 is at an elevation above theinvert of the on inlet 105 such that a flow rates exceeding the designflow rate, stormwater will pass over the top of vertical baffle 120.

Vertical baffle 120 may divide the chamber defined by stormwatertreatment device 100 into an inlet side and an outlet side.

In one embodiment, a bottom of vertical baffle 120 may be positioned tooptimize the flow of water in the lower portion 150 of stormwatertreatment device 100 and may depending on the size of stormwatertreatment device 100. In one embodiment, the bottom of vertical baffle120 may be at least two feet from the bottom of stormwater treatmentdevice 100. Other placements may be used as is necessary and/or desired.

The stormwater may continue from lower portion 150 of stormwatertreatment device 100 to upper portion 155 of stormwater treatmentdevice. In one embodiment, enhanced settling device 125, such aslamellar tubes, may be positioned between lower portion 150 and upperportion 155.

In embodiments, enhanced settling device 125 may comprise a plurality ofsheets, with each sheet formed with ridges at an angle. In oneembodiment, the sheets may be placed so that the ridges in adjacentsheets are parallel, forming tubes positioned at an angle to thevertical. In another embodiment, the sheets may be placed such that theridges in adjacent sheets are perpendicular, creating a series oftortuous paths.

In one embodiment, the bottom of enhanced settling device 125 may beabove the bottom of vertical baffle 120.

One or more flow diverter 130, 131, and 132 may be provided in lowerportion 150 of stormwater treatment device 100 and may divert the flowof the untreated stormwater so that the suspended contaminants have moretime to fall out of suspension. In one embodiment, flow diverters 130,131, and/or 132 may further prevent inflowing untreated stormwater fromre-suspending the contaminants.

In one embodiment, flow diverters 130, 131, and/or 132 may be plates. Inone embodiment, the plates may be planar. In one embodiment, a secondflow diverter (131) may be attached to wall 115 in the direction of theangle of the lamellar tubes such that the centerline of the second flowdiverter coincides with the centerline of wall 115. A third flowdiverter 132 may be attached to wall 115 opposite the second flowdiverter 131 such that the centerline of the third flow divertercoincides with the centerline of the wall 115. Two or more of the flowdiverters may be manufactured as a single piece. The sagitta of eachflow diverter may be between 3 inches and 30% of the distance to theopposite wall or baffle. For example, 14 inches may be the upper limitfor a 48″ diameter tank.

Outlet control diverter 135 may further restrict the flow of thestormwater before it can exit outlet 110. In one embodiment, outletcontrol diverter may prevent stormwater from flowing directly from lowerportion 150 to upper portion 155 and out of outlet 110 without a changeof flow direction. Outlet control diverter 135 may further causesuspended contaminants to fall out of suspension.

Outlet control diverter 135 may be planar, and may be attached to wall115 below outlet 110 such that outlet control diverter 135 plate has thesame centerline as outlet 110, and outlet control diverter 135 forms anangle of 45 degrees to 135 degrees from horizontal.

Outlet control diverter 135 may include a horizontal bottom piece at thesame elevation as outlet 110 invert and two vertical side pieces. Thefirst vertical side piece may project from one side of outlet 110 andmay be substantially parallel to a vertical plane bisecting outlet 110.The second vertical side piece may be substantially perpendicular to thefirst vertical side piece and parallel to a tangent off the wall 115taken at the centerline of the outlet. The bottom piece and two verticalside pieces form an opening through which water can reach outlet 110. Inone embodiment, each vertical side piece may project at least 4 inchesfrom the horizontal side piece.

While the dimensions of outlet control diverter 135 and its parts mayvary based on the size of stormwater treatment device 100, in oneembodiment, the first vertical side piece may project at least 6 inchesfrom one side of outlet 110, and the second vertical piece may be atleast 8 inches in length. The dimensions may vary with the size ofstormwater treatment device 100, with, in general, larger devices havinglarger elements, and smaller devices having smaller elements. In oneembodiment, the second vertical side piece may be curved. The size ofthe side pieces may be selected to maximize the path length to outlet110 while still staying close to the size of outlet 110.

In one embodiment, the largest dimension perpendicular to a verticalplane bisecting inlet 105 may be equal to or less than the largestdimension parallel to the vertical plane bisecting inlet 105. Forexample, the length between inlet 105 and outlet 110 may be greater thanthe width of the chamber. This may be useful, for example, if thechamber is rectangular in shape. The angle between the vertical planebisecting inlet 105 and a vertical plane bisecting outlet 110 may bebetween 45 and 315 degrees. Other angles may be used as is necessaryand/or desired.

Referring to FIGS. 7 and 8 , exemplary details on enhanced settlingdevice 125 are provided according to embodiments. Enhanced settlingdevice 125 may include a plurality of lamellar tubes. The lamellar tubesmay have any suitable shape; in one embodiment, as illustrated in FIG. 7, the lamellar tubes may have a hexagonal shape. Other tube shapes, suchas rectangles, parallelograms, circles, etc. may be used as well. In oneembodiment, the dimensions of each tube may be selected to minimize theheight of each channel provided by the tubes, which minimizes thesettling distance.

In one embodiment, the lamellar tubes in enhanced settling device 125may be positioned at an angle from the horizontal. In one embodiment,water flowing through enhanced settling device 125 must reversedirection at least twice in order to enter the opening in outlet controldiverter 135. For example, the storm water reverses direction intravelling from lower portion 150 to upper portion 155 via enhancedsettling device 125, and again from enhanced settling device 125 tooutlet 110. Outlet diverter 135 may require still another change ofdirection.

In one embodiment, the angle may be selected to optimize settling versusself-cleaning of the tubes in enhanced settling device 125. For example,the angle may be between 45 and 75 degrees. Other angles may be used asis necessary and/or desired.

In one embodiment, the lamellar tubes in enhanced settling device 125may be positioned at different angles to the horizontal. For example, afirst subset of lamellar tubes may be positioned at a first angle to thehorizontal, a second subset of lamellar tubes may be positioned at asecond angle to the horizontal, etc. The angle(s) may be selected as isnecessary and/or desired.

In one embodiment, as shown in FIG. 2A, vertical baffle 120 may includeone or more vanes 140 that may extend down from the top of verticalbaffle 120 on the inlet side that help prevent the formation of vorticesin the flow on the inlet side. For example, vanes 140 may extend from12-36″ below the top of vertical baffle 120 at a distance from 1-5″ outfrom the baffle. The dimensions of vanes 140 may vary depending on thesize of stormwater treatment device 100. In one embodiment, at least onevane 140 may be positioned at least 3″ from the point where the baffle120 meets the wall of stormwater treatment device 100 while the othervane 140 may be positioned at least 3″ from the point where the otherside of the baffle 120 meets the wall of stormwater treatment device100. Any arrangement of vanes 140 may be symmetrical about a verticalplane bisecting and perpendicular to vertical baffle 120.

In another embodiment, as shown in FIG. 2B, vane 140 may be providedwith a horizontal orientation.

Stormwater treatment device 100 may be configured to cause the waterflow within stormwater treatment device 100 to change direction severaltimes. The purpose of the direction changes is to optimize the time thatthe stormwater spends within stormwater treatment device 100. Becausegravity settling takes time, because volume and flow may be limited bythe dimensions of stormwater treatment device 100, this directionchanges use the volume within stormwater treatment device 100 aseffectively as possible.

Referring to FIGS. 9 and 10 , an isometric view and a sectional view ofa stormwater treatment device are provided, respectively, according toanother embodiment. Stormwater treatment device 900 may define a chamberincluding inlet 905, outlet 910, wall 915, inner chamber wall 960, andsupports 965. In one embodiment, stormwater carrying contaminants mayenter inlet 905 and may fall to outer chamber 950 of stormwatertreatment device 900. The stormwater may then flow through enhancedsettling device 925 into inner chamber 955 of stormwater treatmentdevice 900 and may then exit via outlet 910.

It should be recognized that in an alternate embodiment, enhancedsettling device 925 may be provided in outer chamber 950 of stormwatertreatment device, and stormwater may be provided to inner chamber 965 ofstormwater treatment device 900 via inlet 905. Outlet 910 may beprovided for outer chamber 950, so that when stormwater flows throughenhanced settling device 925, it exits stormwater treatment device 900via outlet 910.

Enhanced settling device 925 may be similar to enhanced settling device125, described above.

Referring to FIG. 11 , a method for removing contaminants fromstormwater is disclosed according to one embodiment.

In step 1105, stormwater carrying contaminants flows into the inlet sideof the stormwater treatment device where an expansion allows the fluidvelocity to decrease.

In step 1110, the stormwater flows into a lower portion of thestormwater treatment device unless flow exceeds a certain design flowrate. For example, if the flow is above a certain design flow rate, aquantity of stormwater proportional to the amount of flow above acertain design flow rate will flow over a baffle and directly to anupper portion of the stormwater treatment device while the remainder ofthe flow will flow into the lower portion of the stormwater treatmentdevice.

In step 1115, the stormwater flows into a lower portion and containmentsmay be released from suspension due to gravity settling. Settledcontaminants will accumulate in the lower portion of the stormwatertreatment device.

In step 1120, the stormwater changes direction and may flow up anenhanced settling device, such as lamellar tubes. These tubes provide ashorter settling distance, which reduces the time required for settling.This facilitates the settling of smaller particles. Particles settled inthe enhanced settling device will eventually fall into the lower portionof the stormwater treatment device.

In step 1125, the stormwater exits the enhanced settling device andchanges direction in an upper portion of the stormwater treatmentdevice.

In step 1130, the stormwater reaches an outlet flow diverter and mayflow out of the outlet. In one embodiment, the structure of the outletflow diverter may cause the stormwater to change direction again beforeexiting via the outlet.

It will be appreciated by persons skilled in the art that the presentinvention is not limited by what has been particularly shown anddescribed hereinabove. Rather the scope of the present inventionincludes both combinations and sub-combinations of features describedhereinabove and variations and modifications thereof which are not inthe prior art. It should further be recognized that these embodimentsare not exclusive to each other.

It will be readily understood by those persons skilled in the art thatthe embodiments disclosed here are susceptible to broad utility andapplication. Many embodiments and adaptations of the present inventionother than those herein described, as well as many variations,modifications and equivalent arrangements, will be apparent from orreasonably suggested by the present invention and foregoing descriptionthereof, without departing from the substance or scope of the invention.

Accordingly, while the present invention has been described here indetail in relation to its exemplary embodiments, it is to be understoodthat this disclosure is only illustrative and exemplary of the presentinvention and is made to provide an enabling disclosure of theinvention. Accordingly, the foregoing disclosure is not intended to beconstrued or to limit the present invention or otherwise to exclude anyother such embodiments, adaptations, variations, modifications orequivalent arrangements.

1. A stormwater treatment device, comprising: a chamber having a floorand a wall; an inlet formed in the wall that receives stormwater into aninlet side of the chamber; an outlet formed in the wall that dischargesstormwater from an outlet side of the chamber; a vertical baffle thatdivides at least a portion of the chamber into the inlet side and theoutlet side, wherein the inlet side and the outlet side are in fluidcommunication; an enhanced settling device positioned in the outlet sideof the chamber, wherein a portion of the chamber below a bottom of theenhanced settling device defines a lower portion of the chamber, and aportion of the chamber above a top of the enhanced settling devicedefines an upper portion of the chamber; a flow diverter plate in thelower portion of the chamber; and an outlet control diverter positionedproximate to the outlet; wherein stormwater is received by the inlet ina first flow direction, flows from the inlet side to the lower portionof the chamber in a second flow direction, flows through the enhancedsettling device to an upper portion of the chamber in a third flowdirection, flows through the outlet control diverter in fourth flowdirection, and is discharged by the outlet in a fifth flow direction. 2.The stormwater treatment device of claim 1, further comprising: aplurality of substantially vertical vanes positioned on the verticalbaffle, wherein the plurality of substantially vertical vanes extendinto the inlet side of the chamber.
 3. The stormwater treatment deviceof claim 1, further comprising: a horizontal vane positioned on thevertical baffle, wherein the horizontal vane extends into the inlet sideof the chamber.
 4. The stormwater treatment device of claim 3, furthercomprising a plurality of vertical vanes, wherein the vertical vanesextend from ends of the horizontal vane.
 5. The stormwater treatmentdevice of claim 1, wherein the enhanced settling device comprises aplurality of tubes and each tube is positioned at an angle from the walltoward the vertical baffle.
 6. The stormwater treatment device of claim1, wherein the enhanced settling device comprises a plurality of tubes,and a first subset of the plurality of tubes is positioned at a firstangle to the horizontal, and a second subset of the plurality of tubesis positioned at a second angle to the horizontal.
 7. The stormwatertreatment device of claim 1, wherein a top of the enhanced settlingdevice is below a lower surface of the outlet control diverter.
 8. Thestormwater treatment device of claim 1, wherein stormwater having a flowrate above a certain value flows over the vertical baffle.
 9. Thestormwater treatment device of claim 1, wherein the outlet controldiverter comprises a bottom piece and two vertical side pieces, whereinan opening for receiving stormwater is defined by the bottom piece, oneof the vertical side pieces, and the wall.
 10. The stormwater treatmentdevice of claim 1, wherein changes in the flow directions optimize atime the stormwater spends in the chamber.
 11. The stormwater treatmentdevice of claim 1, wherein the chamber is cylindrical.
 12. Thestormwater treatment device of claim 1, wherein the chamber isrectangular.
 13. A method for removing suspended contaminants fromstormwater, comprising: receiving, at an inlet of a stormwater treatmentdevice having a chamber, stormwater comprising suspended contaminants,wherein the stormwater flows into an inlet side of the stormwatertreatment device and a fluid velocity of the stormwater decreases;receiving, in a lower portion of the stormwater treatment device, thestormwater; receiving, in an enhanced settling device, the stormwaterfrom the lower portion, wherein the stormwater changes direction to flowup the enhanced settling device into an upper portion of the chamber onan outlet side of the chamber; receiving, at an outlet control diverter,the stormwater from the upper portion, wherein the stormwater changesdirection to be received by the outlet control diverter; anddischarging, at an outlet, the stormwater.
 14. The method of claim 13,wherein the enhanced settling device comprises a plurality of tubes andeach tube is positioned at an angle from an outer wall of the stormwatertreatment device.
 15. The method of claim 13, wherein the enhancedsettling device comprises a plurality of tubes, and a first subset ofthe plurality of tubes is positioned at a first angle to the horizontal,and a second subset of the plurality of tubes is positioned at a secondangle to the horizontal.
 16. The method of claim 13, wherein a top ofthe enhanced settling device is below a lower surface of the outletcontrol diverter.
 17. The method of claim 13, wherein stormwater havinga flow rate above a certain value flows over a vertical baffle.
 18. Themethod of claim 13, wherein the outlet control diverter comprises abottom piece and two vertical side pieces, wherein an opening forreceiving stormwater is defined by the bottom piece, one of the verticalside pieces, and an outer wall of the stormwater treatment device. 19.The method of claim 13, wherein the changes in flow direction optimize atime the stormwater spends in the chamber.
 20. The method of claim 13,wherein the chamber is cylindrical.
 21. The method of claim 13, whereinthe chamber is rectangular.